<html>
<head>
<title>:only-child test</title>
<style>
div:only-child {
  color: red;
}

div {
  display: inline-block;
  margin: 6px;
  border-width: 1px;
}
</style>
</head>
<body>
<div>
  <div>I am an only child.</div>
</div>

<div>
  <div>I am the 1st sibling.</div>
  <div>I am the 2nd sibling.</div>
  <div>I am the 3rd sibling, <div>but this is an only child.</div></div>
</div>

</body>
</html>
